You asked for a summary of (1) environmental concerns about using fertilizer containing phosphorus and (2) state laws that ban its use.

SUMMARY

Phosphorus is a naturally occurring mineral nutrient that is necessary for plant growth. It is an essential part of photosynthesisand helps plants to mature properly.

But high phosphorus levels in water bodies can lead to excessive algae and aquatic plant growth which can harm aquatic life and impair recreational use. It can cause toxic algae blooms, reduce water clarity, and deplete oxygen levels. Low water oxygen levels can stress or kill fish and other aquatic animals, among other things.

A library search generated 11 states that ban phosphorus fertilizer use or sale; all laws passed in the last 10 years.

Generally, these laws prohibit phosphorus fertilizer application unless it is for (1) curing a lack of necessary phosphorus, (2) establishing new turf, or (3) repairing turf. Many also exempt agricultural uses, commercial or sod farms, gardening, and golf courses. Most of the states prohibit fertilizer application on impervious, frozen, or saturated surfaces. Other provisions included in some states' laws are (1) setbacks from water bodies such as lakes or rivers, and (2) sales restrictions such as displaying phosphorus fertilizer separately from other types of fertilizers and posting cautionary information.

A twelfth state, Florida, requires certain local governmental units to adopt a model ordinance restricting fertilizer use and encourages other units to do the same. The model ordinance bans applying fertilizer containing nitrogen or phosphorus during a “prohibited application period.”

ENVIRONMENTAL CONCERN

Nutrients such as phosphorus and nitrogen are essential, naturally occurring elements for plant growth but increased levels of these nutrients can jeopardize water quality. Sewage discharges and fertilizer runoff containing phosphorus contribute to increased nutrient water levels. Runoff or leaching into groundwater can occur when fertilizer is applied at times when (1) it can be removed by rainfall or snowmelt, or (2) land or crops cannot absorb the nutrients.

High concentrations of phosphorus or nitrogen in water bodies can lead to excessive algae and aquatic plant growth (a process called eutrophication) which can impair aquatic life and recreational use. It can cause algae blooms, reduce water clarity, and deplete oxygen levels that can stress or kill fish and other aquatic animals (a condition called hypoxia). According to a Virginia Cooperative Extension report discussing environmental impacts from agricultural phosphorus use, eutrophication can (1) cause fish kills or harm wildlife and livestock by reducing water oxygen content or producing toxins and (2) increase the cost and difficulty of drinking water purification. Decaying algae also produces surface scum, odor, and leads to increased insect populations.

A 2010 interagency report of the National Science and Technology Council's Committee on Environment and Natural Resources (in which the U.S. Environmental Protection Agency (EPA) participated) warns that declining oxygen levels in U.S. waters are forming low-oxygen “dead zones” and destroying habitats. In Region 1 specifically (which includes Connecticut), EPA requires wastewater discharge permits to include phosphorus limits where a discharge may degrade water quality. Connecticut's Department of Energy and Environmental Protection (DEEP) identifies nutrient enrichment as a major water quality issue, highlighting the fact that EPA has emphasized aggressive action to limit phosphorus discharge to surface waters. According to DEEP, there are 21 identified water body segments in the state where nutrient enrichment is contributing to water impairment.

In general, these states prohibit phosphorus fertilizer application unless it is for (1) curing a lack of necessary phosphorus, (2) establishing new turf, or (3) repairing turf. Many states exempt agricultural lands and production, commercial or sod farms, gardening, or golf courses from the ban. And many prohibit applying fertilizer (not only phosphorus fertilizer) on impervious, frozen, or saturated surfaces, or within a certain distance of a water body. Inadvertent application on impervious surfaces must be removed or cleaned up. Some states also have phosphorus fertilizer sale restrictions such as separately displaying phosphorus fertilizer and posting cautionary information.

Table 1 summarizes the primary elements of each state's ban. It does not provide enforcement and penalty information or discuss applying certain manures to land or soil, which many states allow. Some of these state laws prohibit local governmental units from adopting more restrictive requirements, with some exceptions. And some laws require the state to provide consumers with information such best practices for phosphorus lawn fertilizer and restrictions on use. For this and other information, the table provides a link to each state law.

Florida law requires certain counties and municipalities located in nutrient-impaired watersheds to adopt the state's model ordinance for any fertilizer use in urban landscapes and may adopt more stringent standards if certain conditions are met. The law encourages other counties and municipalities to adopt the ordinance or an equivalent. Among other things, the Model Ordinance for Florida-Friendly Fertilizer Use on Urban Landscapes (1) establishes fertilizer content and application rates; (2) bans applying fertilizer containing phosphorus or nitrogen to saturated soils, impervious surfaces, or during a “prohibited application period”; (3) establishes a three-foot to ten-foot setback for application near water sources such as streams, lakes, or wetlands; and (4) exempts agriculture.